Extrapleural airway device and method

ABSTRACT

This is directed to improving the gaseous exchange in a lung of an individual and particularly, this is directed to improving the gaseous exchange in individuals having chronic obstructive pulmonary disease. It generally includes fluidly connecting the lung to an extrapleural airway such as the trachea. In one variation, a conduit is deployed to place the lung and the trachea in fluid communication which allows trapped oxygen-reduced air to pass directly out of the lung and into the trachea. Removing nonfunctional air from the lung tends to improve the gaseous exchange of oxygen into the blood and decompress hyper-inflated lungs. Sealant and biocompatible adhesives may be provided on the exterior of the conduit to prevent side flow, leaks and to otherwise prevent air from entering spaces not intended to receive air such as the pleura space.

REFERENCE TO PRIOR APPLICATIONS

This application claims benefit of 60/393,964 Jul. 5, 2002.

FIELD OF THE INVENTION

This is directed to improving the gaseous exchange in a lung of anindividual and more particularly, this is directed to improving thegaseous exchange in a lung of an individual having chronic obstructivepulmonary disease.

BACKGROUND OF THE INVENTION

In 1995, the American Lung Association (ALA) estimated that between15-16 million Americans suffered from chronic obstructive pulmonarydisease (COPD) which includes diseases such as chronic bronchitis,emphysema, and some types of asthma. The ALA estimated that COPD was thefourth-ranking cause of death in the U.S. The ALA estimates that therates of emphysema is 7.6 per thousand population, and the rate forchronic bronchitis is 55.7 per thousand population.

Those inflicted with COPD face disabilities due to the limited pulmonaryfunctions. Usually, individuals afflicted by COPD also face loss inmuscle strength and an inability to perform common daily activities.Often, those patients desiring treatment for COPD seek a physician at apoint where the disease is advanced. Since the damage to the lungs isirreversible, there is little hope of recovery. Most times, thephysician cannot reverse the effects of the disease but can only offertreatment and advice to halt the progression of the disease.

To understand the detrimental effects of COPD, the workings of the lungsrequires a cursory discussion. The primary function of the lungs is topermit the exchange of two gasses by removing carbon dioxide fromarterial blood and replacing it with oxygen. Thus, to facilitate thisgaseous exchange, the lungs provide a blood gas interface. The oxygenand carbon dioxide move between the gas (air) and blood by diffusion.This diffusion is possible since the blood is delivered to one side ofthe blood-gas interface via small blood vessels (capillaries). Thecapillaries are wrapped around numerous air sacs called alveoli whichfunction as the blood-gas interface. A typical human lung contains about300 million alveoli.

The air is brought to the other side of this blood-gas interface by anatural respiratory airway, hereafter referred to as a natural airway orairway, consisting of branching tubes which become narrower, shorter,and more numerous as they penetrate deeper into the lung. As shown inFIG. 1A, the trachea 10 branches into the right bronchi (not shown) andleft bronchi 20 which divide into lobar, then segmental bronchi. Theleft bronchi 20 is shown branching into secondary bronchi 24 each ofwhich further divides into tertiary bronchi 30. Ultimately, thebranching continues down to the bronchioles 100 and terminal bronchioles40 which lead to the alveoli (not shown). Plates of cartilage may befound as part of the walls throughout most of the airways from thetrachea to the bronchi. The cartilage plates become less prevalent asthe airways branch. Eventually, in the last generations of the bronchi,the cartilage plates are found only at the branching points. The bronchiand bronchioles may be distinguished as the bronchi lie proximal to thelast plate of cartilage found along the airway, while the bronchiolelies distal to the last plate of cartilage. The bronchioles 100 are thesmallest airways that do not contain alveoli. The function of thebronchi and bronchioles is to provide conducting airways that lead airto and from the gas-blood interface. However, these conducting airwaysdo not take part in gas exchange because they do not contain alveoli.Rather, the gas exchange takes place in the alveoli which are found inthe distal-most end of the airways.

Breathing involves the lungs, the rib cage, the diaphragm and abdominalwall. During inspiration, inspiratory muscles contract increasing thevolume of the chest cavity. As a result of the expansion of the chestcavity, the pleural pressure, the pressure within the chest cavity,becomes sub-atmospheric. Consequently, air flows into the lungs and thelungs expand. During unforced expiration, the inspiratory muscles relaxand the lungs begin to recoil and reduce in size. The lungs recoilbecause they contain elastic fibers that allow for expansion, as thelungs inflate, and relaxation, as the lungs deflate, with each breath.This characteristic is called elastic recoil. The recoil of the lungscauses alveolar pressure to exceed atmospheric pressure causing air toflow out of the lungs and deflate the lungs. ‘If the lungs’ ability torecoil is damaged, the lungs cannot contract and reduce in size fromtheir inflated state. As a result, the lungs cannot evacuate all of theinspired air.

In addition to elastic recoil, the lung's elastic fibers also assist inkeeping small airways open during the exhalation cycle. This effect isalso known as “tethering” of the airways. Such tethering is desirablesince small airways do not contain cartilage that would otherwiseprovide structural rigidity for these airways. Without tethering, and inthe absence of structural rigidity, the small airways collapse duringexhalation and prevent air from exiting thereby trapping air within thelung.

Emphysema is characterized by irreversible biochemical destruction ofthe alveolar walls that contain the elastic fibers, called elastin,described above. The destruction of the alveolar walls results in a dualproblem of reduction of elastic recoil and the loss of tethering of theairways. Unfortunately for the individual suffering from emphysema,these two problems combine to result in extreme hyperinflation (airtrapping) of the lung and an inability of the person to exhale. In thissituation, the individual will be debilitated since the lungs are unableto perform gas exchange at a satisfactory rate.

One further aspect of alveolar wall destruction is that the airflowbetween neighboring air sacs, known as collateral ventilation orcollateral air flow, is markedly increased as when compared to a healthylung. While alveolar wall destruction decreases resistance to collateralventilation, the resulting increased collateral ventilation does notbenefit the individual since air is still unable to flow into and out ofthe lungs. Hence, because this trapped air is rich in CO₂, it is oflittle or no benefit to the individual.

Chronic bronchitis is characterized by excessive mucus production in thebronchial tree. Usually there is a general increase in bulk(hypertrophy) of the large bronchi and chronic inflammatory changes inthe small airways. Excessive amounts of mucus are found in the airwaysand semisolid plugs of this mucus may occlude some small bronchi. Also,the small airways are usually narrowed and show inflammatory changes.

Currently, although there is no cure for COPD, treatment includesbronchodilator drugs, and lung reduction surgery. The bronchodilatordrugs relax and widen the air passages thereby reducing the residualvolume and increasing gas flow permitting more oxygen to enter thelungs. Yet, bronchodilator drugs are only effective for a short periodof time and require repeated application. Moreover, the bronchodilatordrugs are only effective in a certain percentage of the population ofthose diagnosed with COPD. In some cases, patients suffering from COPDare given supplemental oxygen to assist in breathing. Unfortunately,aside from the impracticalities of needing to maintain and transport asource of oxygen for everyday activities, the oxygen is only partiallyfunctional and does not eliminate the effects of the COPD. Moreover,patients requiring a supplemental source of oxygen are usually neverable to return to functioning without the oxygen.

Lung volume reduction surgery is a procedure which removes portions ofthe lung that are over-inflated. The improvement to the patient occursas a portion of the lung that remains has relatively better elasticrecoil which allows for reduced airway obstruction. The reduced lungvolume also improves the efficiency of the respiratory muscles. However,lung reduction surgery is an extremely traumatic procedure whichinvolves opening the chest and thoracic cavity to remove a portion ofthe lung. As such, the procedure involves an extended recovery period.Hence, the long term benefits of this surgery are still being evaluated.In any case, it is thought that lung reduction surgery is sought inthose cases of emphysema where only a portion of the lung isemphysematous as opposed to the case where the entire lung isemphysematous. In cases where the lung is only partially emphysematous,removal of a portion of emphysematous lung which was compressinghealthier portions of the lung allows the healthier portions to expand,increasing the overall efficiency of the lung. If the entire lung isemphysematous, however, removal of a portion of the lung removes gasexchanging alveolar surfaces, reducing the overall efficiency of thelung. Lung volume reduction surgery is thus not a practical solution fortreatment of emphysema where the entire lung is diseased.

Both bronchodilator drugs and lung reduction surgery fail to capitalizeon the increased collateral ventilation taking place in the diseasedlung. There remains a need for a medical procedure that can alleviatesome of the problems caused by COPD. There is also a need for a medicalprocedure that alleviates some of the problems caused by COPDirrespective of whether a portion of the lung, or the entire lung isemphysematous. The production and maintenance of collateral openingsthrough an airway wall allows air to pass directly out of the lungtissue responsible for gas exchange. These collateral openings serve todecompress hyper-inflated lungs and/or facilitate an exchange of oxygeninto the blood.

Methods and devices for creating, and maintaining collateral channelsare discussed in U.S. patent application Ser. No. 09/633,651, filed onAug. 7, 2000; U.S. patent application Ser. Nos. 09/947,144, 09/946,706,and 09/947,126 all filed on Sep. 4, 2001; U.S. Provisional ApplicationNo. 60/317,338 filed on Sep. 4, 2001; U.S. Provisional Application No.60/334,642 filed on Nov. 29, 2001; U.S. Provisional Application No.60/367,436 filed on Mar. 20, 2002; and U.S. Provisional Application No.60/374,022 filed on Apr. 19, 2002; and U.S. Provisional Application No.60/387,163, filed Jun. 7, 2002 each of which is incorporated byreference herein in its entirety.

Notwithstanding the above, a technique for improving the gaseousexchange in a lung as described herein is still desirable.

SUMMARY OF THE INVENTION

The devices and methods described herein serve to improve the gaseousexchange in the lungs. In one variation of the present invention, anextrapleural or extraparenchymal airway such as the trachea is fluidlyconnected to the lung with a conduit. The conduit includes a first endportion, a second end portion and a passageway extending between the endportions. The end portions are adapted to secure the conduit to thetissue structures such that the extrapleural airway is in direct fluidcommunication with the lung.

In one variation a method for improving gas exchange in the lungcomprises creating a channel in each of the extrapleural airway wall andthe lung or pleural wall prior to the step of fluidly connecting thetrachea to the lung. The surgically created channels or openings may becreated with an instrument that emits energy such as radio frequencyenergy. Once the channel(s) are created in the tissue walls, a conduitmay be deployed to provide a passageway for trapped air to flow directlyfrom the lung and into the trachea.

The method may also comprise the step of fixing the extra pleural airwaywall to the pleural membrane of the lung prior to creating the channeltherethrough. The step of fixing may be performed by deploying anadhesive between the wall and membrane. Also, the step of fixing may beperformed by deploying a tissue fastener. The tissue fastener maycomprise a body which extends through the wall and the membrane. Thetissue fastener has two end portions which are adapted to hold the walland the membrane together.

In another variation, the conduit includes a center section anddeflectable extension members wherein the opposing extension members maybe deflected to sandwich tissue therebetween. Other variations includeconduits having various shapes and coatings. In one variation, theconduit includes an extended center section having a length of upwardsof 5 mm.

The inventive method may also include the step of delivering a sealantwith the conduit. The sealant may be disposed on the exterior of theconduit. The sealant may also be delivered separate from the conduit.The sealant serves to secure the conduit in place, hold the tissuestogether, prevent side flow around the conduit, and perhaps affect thewound healing response of the tissue to decrease the likelihood that theconduit will be ejected.

Other aspects of the invention will become apparent upon reading thefollowing detailed description in combination with the correspondingfigures and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates the lungs and the airways used to transport air toand from the blood-gas interface in the lungs.

FIGS. 1B-1D illustrate various states of the natural airways and theblood-gas interface.

FIG. 2A is a schematic illustration of a conduit fluidly connecting theleft lung to the trachea.

FIG. 2B is an enlarged cross sectional view of the deployed conduitshown in FIG. 2A.

FIG. 2C is an enlarged view of an extrapleural airway wall fixed to apleural membrane layer(s) using a tissue fastener element.

FIG. 3 is a cross sectional view of a grommet shaped conduit.

FIGS. 4A-4C are cross sectional views of other types of conduits.

FIG. 5A illustrates a side view of an expandable conduit in anundeployed state.

FIG. 5B illustrates a side view of the conduit of FIG. 5A shown in adeployed shape.

FIG. 5C illustrates a front view of the conduit shown in FIG. 5B.

FIG. 6 is a cylindrical projection of the undeployed conduit shown inFIG. 5A.

FIG. 7A illustrates a side view of another conduit having a tissuebarrier in a deployed state.

FIG. 7B illustrates a side view of another conduit having a tissuebarrier.

FIG. 7C is a front view of the conduit shown in FIG. 7B.

FIG. 7D illustrates a conduit positioned in a channel created in atissue wall.

FIG. 8 is a cross sectional view of the conduit shown in FIG. 7B takenalong line A-A.

FIGS. 9A-9G illustrate a method for deploying the conduit.

FIGS. 10A to 10D illustrate an enlarged cross sectional view of aconduit being deployed in a channel extending through multiple layers oftissue using an inflatable member.

FIGS. 11A-11C depict a lung having both an extra- or transpleural deviceand an intrapleural device deployed therein to improve gaseous exchange.

DETAILED DESCRIPTION OF THE INVENTION

Described herein are methods and devices for improving the gaseousexchange in a lung. More particularly, a method is described forimproving the gaseous exchange in a lung of an individual having chronicobstructive pulmonary disease. The inventive method generally includesfluidly connecting the lung with an extrapleural airway such as thetrachea using a conduit. Once the tissue structures are in fluidcommunication, gas may flow or pass directly from the parenchymal tissueof the lung to the extrapleural airway such as the trachea via thedeployed conduit. By “pass directly” from the lung to the extrapleuralairway it is meant that at least some volume of gas flows direct fromthe inner tissue of the lung to the extrapleural airway without passingthrough typical flow pathways such as the bronchioles, bronchus, etc.which may be constricted or otherwise flow-resistant. Also, by“extrapleural airway” it is meant any airway or portion of an airwaythat is outside of the pleura such as, for example, the trachea ormainstem bronchus. Furthermore, it is intended that in any embodimentdescribed herein, the created path may pass through other tissues thatare located between the extrapleural airway and pleura. Furthermore, theinvention may include creating intra-lung airflow, e.g., betweenseparate lobes of the lung while passing through the pleural surfaces ofthe lobes.

FIGS. 1B-1D are simplified illustrations of various states of an airwayand the blood gas interface. In particular, FIG. 1B shows a naturalairway 100 which eventually branches to a blood gas interface 102. FIG.1C illustrates an airway 100 and blood gas interface 102 in anindividual having COPD. The obstructions 104 impair the passage of gasbetween the airways 100 and the interface 102. FIG. 1D illustrates aportion of an emphysematous lung where the blood gas interface 102expands due to the loss of the interface walls 106 which havedeteriorated due to a bio-chemical breakdown of the walls 106. Alsodepicted is a constriction 108 of the airway 100. A combination of thephenomena depicted in FIGS. 1C-1D may exist in the same lung and lead toinspired air remaining trapped inside the lung. Inspired air may bedepleted of oxygen and occupy space in the parenchymal tissue of thelung (see e.g., reference numeral 50 of FIG. 1A). It is thereforedesirable to create the flow pathways described herein which allow theinspired air to flow directly out of the lung bypassing the obstructedairways. Ridding the lung of the nonfunctional air allows the healthyportions of the lung to expand to a greater volume, improving thegaseous exchange.

FIG. 2A illustrates a technique for fluidly connecting an extrapleuralairway to the lung. In particular, a conduit 52 is shown connecting thetrachea 54 to parenchymal tissue within the left lung 58. The conduitincludes a passageway that extends through three layers of tissueincluding the visceral pleura 60, parietal pleura 62, and the tracheawall 54.

The conduit 52 shown in FIG. 2B is grommet shaped and its end portionsare adapted to secure the conduit in place and hold the tissue wallstogether. FIG. 2B additionally shows a sealant 70 in the spaces betweenthe exterior of the conduit and the edges of the tissue walls definingthe channel. The sealant may serve one or more functions includingsecuring and sealing the conduit in place. For example, the sealant maycomprise an adhesive material which secures the walls and the conduittogether. Also, the sealant may block leaks and side flow of air aroundthe conduit. Leakage around the conduit is undesirable because the airmay enter the chest cavity or pleural space 64. This may lead topneumothorax or pneumomediastinum each of which is undesirable. Also,the sealant material may be a bioactive agent that, for example,encourages fibrotic wound healing. Examples of various sealant andagents include cyanoacrylate, fibrin glue, talc, and substancescomprising talc. However, other substances may be employed. Also, asdescribed herein, the structure or shape of the conduit itself may serveto prevent side flow and leaks as well as provide a passageway for airto flow through.

The present invention may also include the step of fixing or stabilizingthe extrapleural airway wall and the pleural membrane tissue layers at aselected or target region. Fixing these tissue layers together prior tocreating the channel through the layers can lesson the likelihood thatair will enter the pleural space. Indeed, the lung may collapse if airenters the pleural space.

The tissues may be fixed using various techniques. For example, anadhesive or tissue sealant may be injected into the tissue at the targetlocation prior to creating the channels. Also, as shown in FIG. 2C atissue fastener element 80 may be deployed through the tissue layers 82,84, 86 such that the tissue layers are fixed and stabilized prior tocreating the channel for the conduit (not shown). The channel may becreated adjacent the fastener element 80. The tissue fastener may bemade of a biocompatible material such as the materials used for theconduit. The tissue fastener may include a body and two enlarged endportions. The end portions shall be large enough such that the tissuelayers are held together. Also, once the step of creating the channel iscompleted and a conduit is deployed, the fixing mechanism such as thetissue fastener may be removed because the conduit holds the tissuestogether. Alternatively, the tissue fastener may be left in place afterthe conduit is deployed.

Still other techniques may be employed to affix the parietal pleura tothe visceral pleura such as heating, melting and coagulating devices. Anelectrode or heating element may be positioned at the target region andenergy may be sent to the tissue layers causing the tissue layers tocoagulate together. This fixing step may be performed 1 day or more inadvance of creating the channels through the tissue layers.

Additionally, it is contemplated that during the procedures describedherein the lung opposite the lung being treated may be isolated andventilated such that the lung being treated is not used to carry outgaseous exchange during the procedure.

FIGS. 3 and 4 respectively illustrate conduits 150, 160 having a body orcenter section extending between two enlarged end portions 152, 162. Anopen passageway 154, 164 extends from one end to the other.

The conduit in FIG. 3 is grommet shaped. A conduit of this type may bemade of a plastic or metal. For example, the conduit may be abiocompatible rubber which is squeezed into position within a surgicallycreated channel extending through the tissue walls. By “channel” it ismeant to include but not be limited to any opening, hole, slit, channelor passage created in an airway wall. The channel may be created intissue having a discrete wall thickness and the channel may extend allthe way through the wall. Also, a channel may extend through lung tissuewhich does not have well defined boundaries such as, for example,parenchymal tissue.

In any event, when conduit 150 is positioned in such a channel, theenlarged end portions 152 hold the tissue walls together and tend toprevent side flow (or leakage) around the conduit. Additionally, theconduit may be selected such that it is slightly oversized relative tothe channel in which it is placed. The exterior of the conduit will thuspress against the edges of the tissue walls eliminating side spaces forair to enter.

FIG. 4A illustrates another grommet shaped conduit having tapered endportions 162. The tapered end portions serve the same purposes as thoseidentified above. Also, the tapered end portions may make the conduitless traumatic to deploy since the tapered end portions have a graduallyincreasing diameter.

FIGS. 4B and 4C illustrate another conduit 170 which may be deployed tofluidly connect the lung with an extrapleural airway. The conduit 170includes a body 172 and an end portion 174A, B extending from each endof the body. A passageway 176 extends through the conduit. The endportions 174A, B are bowl-shaped in this example and are configured suchthat they may be inverted. Both end portions are shown inverted in FIG.4C. The invertible end portions thus can sandwich tissue when theconduit is positioned at a target site. Also, the conduit may beelastomeric to provide increased resilience and compression of thesandwiched tissue layers such that side flow and leakage around theconduit is minimized.

FIGS. 5A-5C illustrate another conduit in accordance with the presentinvention having a center section 208 and at least one extension member(or finger) 202 extending from each end of the center section. Theextension members, as will be discussed in more detail below, arecapable of deflecting or outwardly bending to secure the conduit in anopening created in an airway wall thereby maintaining the patency of theopening. The extension members may deflect such that opposing extensionmembers may form a V, U, C, horseshoe, or other type of shape whenviewed from the side.

Additionally, the conduits shown in FIGS. 5A-5C include a center-controlsegment 235 which restricts or limits radial expansion of the centersection. The center-control segments are adapted to straighten as thecenter section is radially expanded. Once the center-control segmentsbecome straight or nearly straight, radial expansion of the conduit isprevented. In this manner, the radial expansion of the conduit may beself controlled.

The conduits described herein may have various states (configurations orprofiles) including but not limited to (1.) an undeployed state and (2.)a deployed state.

The undeployed state is the configuration of the conduit when it is notsecured in an opening in an airway wall and, in particular, when itsextension members (or fingers) are not outwardly deflected to engage theairway wall. FIG. 5A is a side view of a conduit 200 in an undeployedstate. As shown in this figure, extension members 202A, 202B extendstraight from the ends 210, 212 respectively of center section 208. Theextension members shown in this example are parallel. However, theinvention is not so limited and the extension members need not beparallel.

The deployed state is the configuration of the conduit when it issecured in a channel created in an airway wall and, in particular, whenits extension members are outwardly bent to engage the airway wall suchthat the conduit is fixed in the opening. An example of a conduit in itsdeployed configuration is shown in FIGS. 5B and 5C. FIG. 5B is a sideview of a conduit in its deployed state and FIG. 5C shows a front viewof the conduit of FIG. 5B.

As shown in FIGS. 5A-5C, the conduit includes a center section 208having a short passageway. This center section may be a tubular-shapedopen-frame (or mesh) structure having a plurality of ribs. As discussedherein, a cover, coating or barrier may be coaxially disposed around theframe. Alternatively, the center section may be a sheet of materialrolled or folded into shape.

The axial length of the center section or passageway may be relativelyshort. In FIGS. 5A-5C, the passageway's length is about equal to thewidth of a wire segment or rib. Here, the center section serves as abridge or junction for the extension members and it is not required tobe long. The axial length of the passageway may therefore be less than 1mm and even approach 0 mm. In one example, the length of the centersection is less than twice the square root of a cross sectional area ofthe center section. However, the center section may also havepassageways which have lengths greater than 1 mm.

Indeed, when the conduit is used to place the lung and the trachea influid communication, and when the lung is not in contact with thetrachea, the center section may have a length of 0.5-50 mm and perhaps5-10 mm.

The overall length (L) of the conduit may be distinguished from thelength of the center section because the overall length includes thelengths of the extension members. Further, the overall length (L) isdependent on which state the conduit is in. The overall length of theconduit will typically be shorter when it is in a deployed state asshown in FIG. 5B than when it is in an undeployed state as shown in FIG.5A. The overall length (L) for a deployed conduit may be less than 6 mmand perhaps, between 1 and 20 mm.

FIG. 5C shows a front view of the conduit 200 shown in FIG. 5B. FIG. 5Cshows the passageway having a hexagonal (or circular) cross section. Thecross-section, however, is not so limited: The cross section may becircular, oval, rectangular elliptical, or any other multi-faceted orcurved shape. The inner diameter (D₁) of the center section, whendeployed, may range from 1 to 10 mm and perhaps, from 2 to 5 mm.Moreover, in some variations, the cross-sectional area of thepassageway, when deployed, may be between 0.2 mm² to 300 mm² and perhapsbetween 3 mm² and 20 mm².

As mentioned above, extending from the ends of the center section 208are extension members 202A, 202B which, when the conduit is deployed,form angles A1, A2 with a central axis of the passageway. When viewedfrom the side such as in FIG. 5B, opposing extension members may have aV, U, C, horseshoe or other shape. The extension members 202A, 202B maythus outwardly rotate until they sandwich tissue between opposingextension members.

The angles A1, A2 may vary and may range from, for example, 30 to 150degrees, 45 to 135 degrees and perhaps from 30 to 90 degrees. Opposingextension members may thus form angles A1 and A2 of greater than 90degrees when the conduit is deployed in a channel. For example, anglesA1 and A2 may range from 90 to 125 degrees when the conduit is deployed.The greater angles tend to sandwich the pleural tissue layers betweenthe opposing extension members preventing gas from entering the pleuralspace. However, the conduits of the present invention are not so limitedand the angles may be further increased or decreased.

Moreover, the angle A1 may be different than angle A2. Accordingly, theconduit may include proximal extension members which are parallel (ornot parallel) to the distal extension members. Additionally, the anglecorresponding to each proximal extension member may be different oridentical to that of another proximal extension member. Likewise, theangle corresponding to each distal extension member may be different oridentical to that of another distal extension member.

The extension members may have a length between 1 and 20 mm and perhaps,between 2 and 6 mm. Also, with reference to FIG. 5C, the outer diameter(D₂) of a circle formed by the free ends of the extension members mayrange from 2 to 20 and perhaps, 3 to 10 mm. However, the dimensionsdisclosed above are provided as examples and the invention is notintended to be limited to only the scope of the examples. Further, thelength of the distal extension members may be different than the lengthof the proximal extension members. The length of the distal extensionmembers may be, for example, longer than that of the proximal extensionmembers. Also, the lengths of each proximal extension member may bedifferent or identical to that of the other proximal extension members.Likewise, the lengths of each distal extension member may be differentor identical to that of the other distal extension members.

The number of extension members on each end of the center section mayalso vary. The number of extension members on each end may range from2-20 and perhaps, 3-10 or 6-10. Also, the number of proximal extensionmembers may differ from the number of distal extension members for aparticular conduit. Moreover, the extension members may be symmetricalor non-symmetrical about the center section. The proximal and distalextension members may also be arranged in an in-line pattern or analternating pattern. The extension members may also have openings topermit tissue ingrowth for improved retention.

The shape of the extension members may also vary. They may beopen-framed and somewhat petal-shaped as shown in FIGS. 5A-5C. In thesefigures, the extension members 202A, 202B comprise wire segments or ribsthat define openings or spaces between the members. However, theinvention is not so limited and the extension members may have othershapes. The extension members may, for example, be solid or they may befilled.

The conduit may be constructed to have a low profile delivery state. Thedelivery state is the configuration of the conduit when it is beingdelivered through an airway or a working channel of a bronchoscope,endoscope, or other delivery tool. The maximum outer diameter of theconduit in its delivery state must therefore be such that it may fitwithin the delivery tool, instrument, or airway.

In one variation, the conduit has a small diameter when in its deliverystate and is radially expandable such that it may be radially expandedto a larger size upon deployment. For example, the conduit may be sizedfor insertion into a bronchoscope having a 2 mm or larger workingchannel. Upon deployment, the conduit may be expanded to an increasedinternal diameter (e.g., 3 mm.) However, the invention is not limited tosuch dimensions. It is contemplated that the conduits 200 may havecenter sections that are expanded into a larger profile from a reducedprofile, or, the center sections may be restrained in a reduced profile,and upon release of the restraint, return to an expanded profile.

Additionally, the conduit need not have a smaller delivery state. Invariations where the center section is not able to assume a secondsmaller delivery profile, a maximum diameter of the first or deployedprofile will be sufficiently small such that the conduit may be placedand advanced within an airway or a working channel of a bronchoscope orendoscope. Also, in cases where the conduit is self-expanding, thedeployed shape may be identical to the shape of the conduit when theconduit is at rest or when it is completely unrestrained.

The conduit 200 shown in FIGS. 5A-5C also includes diametric-controlsegments, tethers, or leashes 235 to control and limit the expansion ofthe center section 208 when deployed. This center-control segment 235typically is shaped such that when the conduit radially expands, thecenter-control segment bends until it is substantially straight or nolonger slack. Such a center-control segment 235 may be circular orannular shaped. However, its shape may vary widely and it may have, forexample, an arcuate, semi-circular, V, or other type of shape whichlimits the expansion of the conduit.

Typically, one end of the center-control segment is attached or joinedto the center section at one location (e.g., a first rib) and the otherend of the center-control segment is connected to the center section ata second location (e.g., a rib adjacent or opposite to the first rib).However, the center-control segments may have other constructs. Forexample, the center-control segments may connect adjacent ornon-adjacent center section members. Further, each center-controlsegment may connect one or more ribs together. The center-controlsegments may further be doubled up or reinforced with ancillary controlsegments to provide added control over the expansion of the centersection. The ancillary control segments may be different or identical tothe primary control segments.

FIG. 5B illustrates the conduit 200 in its deployed configuration. Asdiscussed above, the center-control segments 235 may bend or otherwisedeform until they maximize their length (i.e., become substantiallystraight) such as the center-control segments 235 shown in FIG. 5B.However, as discussed above, the invention is not so limited and othertypes of center-control segments may be employed.

The control segments, as with other components of the conduit, may beadded or mounted to the center section or alternatively, they may beintegral with the center section. That is, the control segments may bepart of the conduit rather than separately joined to the conduit withadhesives or welding, for example. The control segments may also bemounted exteriorly or interiorly to the members to be linked.

Additionally, sections of the conduit may be removed to allow areas ofthe conduit to deform more readily. These weakened areas provide anotherapproach to control the final shape of the deployed conduit. Details forcreating and utilizing weakened sections to control the final shape ofthe deployed conduit may be found in U.S. Ser. No. 09/947,144 filed onSep. 4, 2001.

The conduit described herein may be manufactured by a variety ofmanufacturing processes including but not limited to laser cutting,chemical etching, punching, stamping, etc. For example, the conduit maybe formed from a tube that is slit to form extension members and acenter section between the members. One variation of the conduit may beconstructed from a metal tube, such as stainless steel, 316L stainlesssteel, titanium, titanium alloy, nitinol, MP35N (anickel-cobalt-chromium-molybdenum alloy), etc. Also, the conduit may beformed from a rigid or elastomeric material that is formable into theconfigurations described herein. Also, the conduit may be formed from acylinder with the passageway being formed through the conduit. Theconduit may also be formed from a sheet of material in which a specificpattern is cut. The cut sheet may then be rolled and formed into a tube.The materials used for the conduit can be those described above.

Additionally, the conduits described herein may be comprised of a shapememory alloy, a super-elastic alloy (e.g., a NiTi alloy), a shape memorypolymer, a polymeric material, an implantable material, a material withrigid properties, a material with elastomeric properties, or acombination thereof. The conduit may be constructed to have a naturalself-assuming deployed configuration, but is restrained in apre-deployed configuration. As such, removal of the restraints causesthe conduit to assume the deployed configuration. A conduit of this typecould be, but is not limited to being, comprised from a shape memoryalloy. It is also contemplated that the conduit could comprise a shapememory alloy such that, upon reaching a particular temperature (e.g.,98.5° F.), it assumes a deployed configuration.

Also, the conduit described herein may be formed of a plasticallydeformable material such that the conduit is expanded and plasticallydeforms into a deployed configuration. The conduit may be expanded intoits expanded state by a variety of devices such as, for example, aballoon catheter.

FIG. 7A illustrates another variation of a conduit 200 having a tissuebarrier 240. The tissue barrier 240 prevents tissue ingrowth fromoccluding the channel or passage of the conduit 200. The tissue barrier240 may coaxially cover the center section from one end to the other orit may only cover one or more regions of the conduit 200. The tissuebarrier may completely or partially cover the conduit. The tissuebarrier 240 may be located about an exterior of the conduit's surface,about an interior of the conduit's surface, or the tissue barrier 240may be located within openings in the wall of the conduit's surface.Furthermore, in some variations of the invention, the center section 208itself may provide an effective barrier to tissue ingrowth. The tissuebarrier, of course, should not cover or block the entrance and exit ofthe passageway such that air is prevented from passing through theconduit's passageway. However, in some constructs, the tissue barriermay partially block the entrance or exit of the passageway so long asair may continue to pass through the conduit's passageway.

The tissue barrier may be formed from a material, or coating that is apolymer or an elastomer such as, for example, silicone, polyurethane,PET, PTFE, or expanded PTFE. Moreover, other biocompatible materialswill work, such as a thin foil of metal, etc. The coatings may beapplied, for example, by either dip coating, molding, spin-coating,transfer molding or liquid injection molding. Or, the tissue barrier maybe a tube of a material and the tube is placed either over and/or withinthe conduit. The tissue barrier may then be bonded, crimped, heated,melted, shrink fitted to the conduit. The tissue barrier may also betied to the conduit with a filament of, for example, a suture material.The tissue barrier may also be placed on the conduit by either solventswelling applications or by an extrusion process. Also, a tissue barriermay be applied by either wrapping a sheet of material about the conduit,or by placing a tube of the material about the conduit and securing thetube to the conduit. Likewise, a tissue barrier may be secured on theinterior of the conduit by positioning a sheet or tube of material onthe inside of the center section and securing the material therein.

FIGS. 7B and 7C respectively illustrate a side view and a front view ofanother conduit 300 having a partial tissue barrier coating. The conduit300 includes a center section 310, a plurality of extension members 320,and a partial tissue barrier 330. The conduit 300 is thus different thanthat shown in FIG. 7A in that the center section is longer and that thetissue barrier 330 only partially covers the extension members 320. Inparticular, the center section 310 shown in FIGS. 7B-7C is cylindricalor tubular-shaped. This shape may be advantageous when a relativelylonger passageway is desired. Also, it is to be understood that theoverall (or three dimensional) shape of the center section, whendeployed, is not limited to the shape shown here. Rather, it may havevarious shapes such as, for example, rectangular, tubular, conical,hour-glass, hemi-toroidal, etc.

Additionally, the tissue barrier 330 covers only a proximal region 350of the extension members and leaves a distal region 340 of the extensionmembers uncovered. The distal region 340 of the extension members 320 isshown as being open-framed. However, the invention is not so limited.The distal region of the extension members may be solid and it mayinclude indentations, grooves, and recesses for tissue ingrowth. Also,the extension members may include small holes for tissue ingrowth. Forexample, the distal region of the extension members may have a densearray of small holes. In any event, the conduits described herein mayinclude at least one region or surface which is susceptible to tissueingrowth or is otherwise adherent to the tissue. Accordingly, tissueingrowth at the distal region 340 of the extension members isfacilitated while tissue growth into the passageway 325 is thwarted.

As shown in FIG. 7D, tissue growth 360 into the uncovered region 340further secures the extension members to the tissue wall 370. The distalregion of the extension members may also include tissue growthsubstances such as epithelial growth factors or agents to encouragetissue ingrowth. Accordingly, conduit 300 may be configured to engagethe tissue wall 370 as well as to allow tissue to grow intopredetermined regions of the conduit.

The conduit shown in FIG. 7A also includes a visualization ring ormarker 242. The marker 242 is visually apparent during a procedure. Themarker is observed as the conduit is placed in a collateral channel and,when the marker is even with the opening of the channel, the conduit maybe deployed. In this manner, the visualization feature facilitatesalignment and deployment of the conduits into channels.

The visualization ring or mark may be a biocompatible polymer and have acolor such as white. Also, the visualization feature may protrude fromthe center section or it may be an indeniation(s). The visualizationmark may also be a ring, groove or any other physical feature on theconduit. Moreover, the visualization feature may be continuous orcomprise discrete segments (e.g., dots or line segments).

The visualization feature may be made using a number of techniques. Inone example, the mark is a ring formed of silicone and is white. Thepolymeric ring may be spun onto the tissue barrier. For example, a clearsilicone barrier may be coated onto the conduit such that it coaxiallycovers the extension members and the center section as shown in FIG. 7A.Next, a thin ring of white material such as a metal oxide suspended inclear silicone may be spun onto the silicone coating. Finally, anothercoating of clear silicone may be applied to coat the white layer. Theconduit thus may include upwards of 1-3 layers including a tissuebarrier, a visualization mark layer, and a clear outer covering.

The shape of the visualization mark is not limited to a thin ring. Thevisualization mark may be large, for example, and cover an entire halfof the conduit as shown in FIG. 7B. The visualization mark may, forexample, be a white coating disposed on the proximal or distal half ofthe conduit. The visualization mark thus may extend from an end of theextension members to the center section of the conduit. As explained inmore detail below, when such a device is deposited into a channelcreated in lung tissue, the physician may observe when one-half of theconduit extends into the channel. This allows the physician to moreaccurately position and deploy the conduit.

Multiple visualization marks or features may be incorporated on theconduit. For example, an elongated conduit may have one proximalvisualization ring and one distal visualization ring to identify theproximal and distal end portions of the conduit during a surgicalprocedure.

The visualization member is made visually apparent for use with, forexample, an endoscope. The visualization feature, however, may also bemade of other vision-enhancing materials such as radio-opaque metalsused in x-ray detection. It is also contemplated that other elements ofthe conduit can include visualization features such as but not limitedto the extension members, tissue barrier, control segments, etc.

The conduits may also include a one-way valve. The valve may bepositioned such that it permits expiration of gas from lung tissue butprevents gas from entering the tissue. The valve may be placed anywherewithin the passageway of the conduit. The valve may also be used asbacterial in-flow protection for the lungs. The valve may also be usedin conjunction with a tissue barrier and the tissue barrier may bedisposed coaxially about the conduit. Various types of one way valvesmay be used as is known to those of skill in the art.

The conduits described herein may also include modified surfaces thatprevent the channel from closing by reducing tissue growth into thepassageway. The modified surfaces may prevent the conduit from beingejected from the channel as the wound heals. The surfaces of the conduitmay be modified, for example, by depositing a bioactive substance ormedicine onto the exterior surface of the conduit.

The bioactive substances are intended to interact with the tissue of thesurgically created channels. These substances may interact with thetissue in a number of ways. They may, for example, accelerate woundhealing such that the tissue grows around the exterior surface of theconduit and then stops growing; encourage growth of the epithelial orendothelial cells; inhibit wound healing such that the injury site(e.g., the channel or opening) does not heal leaving the injury siteopen; and/or inhibit infection (e.g., reduce bacteria) such thatexcessive wound healing does not occur which may lead to excessivetissue growth at the channel thereby blocking the passageway. However,the foregoing statements are not intended to limit the present inventionand there may be other explanations why certain bioactive substanceshave various therapeutic uses in the lung tissue. Again, the bioactivesubstances are intended to prevent the implant from being ejected aswell as prevent the lung tissue from filling or otherwise blocking thepassageway of the conduit.

A variety of bioactive substances may be used with the devices describedherein. Examples of bioactive substances include, but are not limitedto, pyrolitic carbon, titanium-nitride-oxide, paclitaxel, fibrinogen,collagen, thrombin, phosphorylcholine, heparin, rapamycin, radioactive188Re and 32P, silver nitrate, dactinomycin, sirolimus, cell adhesionpeptide. Again, other substances may be used with the conduits such asthose substances which affect the wound healing response (or rate) ofinjured lung tissue.

A cross section of a conduit 300 having a modified surface is shown inFIG. 8. In particular, the conduit 300 comprises an inner frame layer orribs 380 which define a passageway 381 for air to flow through.Coaxially surrounding the frame 380 is a tissue barrier 330.Additionally a visualization coating 384 is disposed on the tissuebarrier 330. The visualization coating 384 is deposited as describedabove. A bioactive substance 386 is deposited on the visualization layereither directly or via a binding layer as described below. In thismanner, the bioactive substance is disposed on an exterior surface ofthe conduit and contacts tissue when the device is deployed in achannel. However, it is contemplated that the conduits may includeadditional layers such as, for example, an additional silicone layerover the visualization layer. Also the order of the layers may bedifferent than that described above. Also, not all coatings andmaterials shown in FIG. 8 are necessary to carry out the presentinvention.

The bioactive layer may also serve as the visualization coating ortissue barrier in some instances. For example, silicone and one or morebioactive substances may be mixed together and disposed on the conduitas a single coating. The single integral layer may serve both tophysically and chemically prevent tissue from filling the conduit'spassageway. It may also be visually apparent during a procedure.

The bioactive substances may be deposited on the exterior surface of theconduit evenly or in discrete (intermittent) amounts. The thickness ofthe coatings may be uniform or the thickness may vary across certainregions of the conduit. This may provide higher therapeutic dosescorresponding to certain regions of the injury site. For example, it maybe desirable to provide a higher concentration of a bioactive substancenear the ends of the conduit rather than in the center section.

The bioactive coatings may be selectively applied by spraying thebioactive substance onto uncovered regions of the conduit. For example,the bioactive substances may be disposed on at least a portion of thetissue barrier or the open-frame (or mesh) structure itself. Thesubstances may also be applied by dipping, painting, printing, and anyother method for depositing a substance onto the conduit surface.Additionally, binding materials may be applied to the exterior surfaceof the conduit upon which the bioactive agents may be deposited.Cross-linked polymers and or biodegradable polymers such as, forexample, chondroitin sulfate, collagen and gelatin may be applied to theexterior surface of the conduit prior to depositing the bioactivesubstances. Additionally, the exterior surface of the conduit may betreated via etching processes or with electrical charge to encouragebinding of the bioactive substances to the conduit.

Again, the bioactive substances herein described are deposited on theexterior of the conduits to, amongst other things, prevent ejection ofthe conduit from the injury site. The bioactive substances also serve toreduce or impede tissue growth into the conduit's passageway. In thismanner, the conduits maintain the patency of channels surgically createdin intrapleural and extrapleural airways allowing air to passtherethrough.

FIGS. 9A-9G illustrate a method of deploying a conduit in accordancewith the present invention. FIG. 9A illustrates the advancement of anaccess device 940 into an airway such as the trachea 920. The accessdevice 940 includes at least one lumen or working channel 942. Theaccess device 940 locates an approximate site 944 for creation of achannel. A bronchoscope or other similar type of endoscope may be usedas the access device 940. In cases where the access device 940 is abronchoscope or similar device, the access device 940 is equipped sothat the surgeon may observe the site for creation of the channel in thetrachea wall. FIG. 9B illustrates a blood vessel detection device 946advanced through the channel 942 of the access device 940 towards thesite 944. An example of a blood vessel detection device is described inU.S. Ser. No. 10/080,344 filed Feb. 21, 2002 which is herebyincorporated by reference in its entirety. The site 944 is inspected todetermine whether a blood vessel is adjacent to the site. It isgenerally desirable to avoid blood vessels when creating a channel inthe tissue walls. The step shown in FIG. 9B is desirable but notnecessary to carry out the present invention. FIG. 9C illustrates thecreation of a channel 112 by a hole-making device 948. Examples ofhole-making devices 948 are disclosed in U.S. Ser. No. 10/079,605 filedFeb. 21, 2002. Furthermore, variations of this invention include the useof devices which are equipped for both detection and hole-making.Examples of such devices are disclosed in U.S. Ser. No. 09/946,706 filedSep. 4, 2001 and U.S. Ser. No. 10/080,344 filed Feb. 21, 2002.

As shown in FIG. 9C, the device 948 may be manipulated to a positionthat is optimal for creation of the collateral channel 112. It is notedthat the access device or the hole-making device may be steerable. Sucha feature assists in positioning any of the devices used in theinventive method. It is also noted that the hole-making device may emitradio frequency energy from its tip to create the hole in the tracheawall 920. The hole-making device is further urged into contact with thelung wall 922. Energy is applied until the device has created a channelthrough both walls 920, 922. Alternatively, the hole-making device mayfeature a needle-type structure which is punched through each of theabove mentioned walls.

Additionally, it is contemplated that during the procedures describedherein the lung opposite the lung being treated may be isolated andventilated so that the lung being treated does not carry out gaseousexchange during the procedure. Also, as described above, the tissuelayers may be fixed together at the target location prior to creatingthe channel through the tissue layers. Fixing the tissue layers togetherprior to creating the channel may reduce the chances that any air mayenter the pleural space between the pleural membrane layers.

FIG. 9D illustrates another variation of the inventive method in which aguide-member, such as a guide-wire 950, or other similar device, isinserted into the channel 112 extending through the walls of the tracheaand the lung. It is noted that the use of a guide-member 950 isoptional.

FIG. 9E illustrates the advancement of a catheter device 952 into thechannel 112. In the variations using a guide-member 950, the catheter952 is advanced over the guide-member 950 and into the channel 112. Onevariation of the inventive method includes the use of a catheter 952which has a conduit-954 attached thereto. Some examples of the conduit954 as well as catheter type delivery devices 952 are disclosedthroughout this disclosure. If the conduit 954 is of the type that isnot self-expanding, the catheter 952 may also be configured to expandthe conduit 954 within the collateral channel 112.

FIG. 9F illustrates deployment of the distal portion of the conduit. Inparticular, FIG. 9F shows deployment of distal extension members 956.Deploying the distal portion of the conduit prior to deploying theproximal portion of the conduit may be desirable because the deployeddistal portion may serve as a grapple. Once the distal portion isdeployed, the assembly may be urged proximally or rearwards to compressthe tissue walls together. The proximal portion of the conduit may thenbe deployed to complete deployment of the conduit. However it is to beunderstood that the conduit may be deployed in various manners and themethod of deployment may depend on the type of conduit deployed. Forexample, as will be described in more detail below, a balloon member maybe actuated to deploy opposing extension members or deflectable fingerssimultaneously such that the tissue walls are sandwiched between theopposing extension members.

Finally, FIG. 9G illustrates the conduit 954 placed within the channelsuch that the trachea 920 is fluidly connected with the lung 924 toallow air to directly pass from the parenchymal tissue 924 to thetrachea. FIG. 9G also shows the withdrawal of the guide-member 950,catheter 952, and the access device 940. As shown by the arrows of FIG.9G, the conduit 954 provides a passageway for trapped non-functional airto be evacuated from a hyper-inflated lung.

As stated above, this method and device may also include use of anadhesive or bioactive material disposed around the conduit to preventair from leaking around the conduit's passageway. Adhesives, bioactivematerials and other substances may be applied to the channel before orafter delivery of the conduit. The substance may be applied or depositedusing, for example, a delivery catheter having at least one lumen. Thedelivery catheter may be manipulated to the site through access device940 or by another means as is known to those of ordinary skill in theart. Once the catheter is positioned the adhesives may be ejected to thetarget site to coat the interior wall of the channel.

It is noted that a variation of the inventive method includes using aguide-wire to create the channel through the tissue walls and leavingthe guide-wire, to extend through the channel. Accordingly, a conduitmay be advanced over the guide-wire into the collateral channel.

It is also to be understood that though the above procedure describesdeploying the conduit from the trachea to the lung, the invention alsoincludes deploying the conduit in a different direction or manner. Thatis, the conduit may be deployed from the parenchymal tissue of the lungto the trachea. In the case that the conduit is deployed from theparenchyma to the trachea, the access device must be manipulated deepinto the lung until a target site is selected. The procedure may then becarried out similarly to that described above except that the initialtarget site is the lung wall. Consequently, the hole-making device mustpenetrate the lung wall prior to penetrating the trachea wall. In eithercase, however, the trachea may be placed in fluid communication with thelung via the deployed conduit.

FIGS. 10A-10D show an enlarged view of one technique for deploying aconduit 900 to fluidly connect the trachea and the lung using aninflatable member. FIG. 10A illustrates the conduit 900 being deliveredinto a channel formed in the trachea 914, the parietal pleura 916, andthe visceral pleura 918. The conduit is shown being delivered via aballoon catheter 902. The conduit 900 may be attached to the deliverydevice 902 using the natural resiliency of the conduit 900. Or, in thosecases where the conduit is spring loaded, the conduit 900 is restrainedin a reduced profile and may be removably affixed to the delivery device902 using an adhesive, or a removable sleeve such as a heat shrink tube.In this example, the balloon catheter 902 has several balloons includinga distal balloon 904, a proximal balloon 906, and a center balloon (notillustrated in FIG. 10A).

FIG. 10B illustrates the inflation of the distal 904 and proximal 906balloons to situate the extension members 908. Accordingly, theextension members 908 form a flange or collar about the tissue walls.These opposing extension members sandwich the tissue walls and securethe conduit in place. The balloons 904, 906 may be inflatedsimultaneously, or in a desired sequence. Deployment of the balloons904, 906 may also serve to center the conduit 900 in the channel.

FIG. 10C illustrates inflation of the center balloon 912 which causesexpansion of the center section 910 of the conduit 900. If the conduit900 is affixed to the delivery device 902, expansion of the centerballoon 912 causes release of the conduit 900 by release of the adhesiveor breaking of the heat shrink tubing (not shown). The attachment may bebioabsorbable and remain in the body, or may remain affixed to thedelivery device 902 and is removed with removal of the delivery device902. Also, it is not necessary for the balloons to be separate. Forexample, a single balloon may have a pre-set expanded shape or theballoon may be restricted in certain areas to prevent expanding in thoseareas.

FIG. 10D illustrates the conduit 900 holding the tissue walls togetherafter the delivery device 902 is removed from the site. Another methodof deploying a conduit includes restraining the conduit about a deliverydevice using a wire or string tied in a slip-knot or a series ofslip-knots. When the conduit is delivered to a desired location, theproximal end of the wire or string may be pulled which releases thewire/string and deploys the conduit.

It should be noted that deployment of conduits is not limited to thatshown above, instead, other techniques may be used to deploy theconduit. For example, spring-loaded or shape memory features may beactuated by mechanical or thermal release and unlocking methods.Additionally, mechanical wedges, lever-type devices, scissors-jackdevices, open chest surgical placement and other techniques may be usedto deploy the conduit. The conduits may be comprised of an elastic orsuper-elastic material which is restrained in a reduced profile fordeployment and expands to its deployed state upon mechanical actuator orrelease.

FIGS. 11A-11C illustrate another variation of the present inventionwhich includes deploying a combination of (1.) an intrapleural deviceand (2.) a transpleural or extrapleural device.

The intrapleural device 200A is deployed in a channel surgically createdin an airway within the lung. The conduit 200A maintains the channel'spatency allowing trapped nonfunctional air to pass directly into theairway 100. This improves gas exchange as the air does not have to passconstrictions 108. The intrapleural conduit may be configured identicalto the transpleural conduit described above or in some cases, theintrapleural devices may have a shorter center section length. Also, asshown in FIGS. 11A-11C more than one intrapleural device may be deployedin combination with at least one transpleural device. While theinvention is not limited to the number of collateral channels which maybe created, it is to be understood that 1 or 2 channels may be placedper lobe of the lung and perhaps, 2-12 channels per individual patient.However, as stated above, the invention includes the creation of anynumber of collateral channels in the lung. This number may vary on acase by case basis. For instance, in some cases in an emphysematouslung, it may be desirable to place 3 or more channels (e.g.,intrapleural or transpleural passageways) in one or more lobes of thelung.

FIGS. 11A-11C also show a transpleural device deployed between the lungand the trachea. The transpleural conduits are configured as describedabove and they may take various shapes. For example, FIG. 11Aillustrates a grommet shaped conduit 200B. FIG. 11B illustrates anelongated conduit 200C which is especially useful when the lung is notin contact with the trachea or when a relatively large distance betweenthe tissue is desired. FIG. 11C illustrates a conduit 200D having angledend portions. Conduit 200D may be deployed, for example, as describedabove using a balloon catheter. Also, as in any of the conduit designs,a sealant may be delivered around the periphery of the conduit toprevent side flow or leakage into the chest cavity or pleural space aswell as prevent the conduit from being ejected.

To reiterate, one or more conduits may be deployed within the lung toallow nonfunctional air trapped in the parenchyma (and other portions ofthe lung) to pass directly into a larger airway via one or moreintrapleural devices such as conduits 200A. Additionally, one or motetranspleural devices such as conduits 200B, 200C, 200D may be deployedin combination with the intrapleural devices to allow air to passdirectly from the lung to an extrapleural airway such as the trachea. Inthis manner, gaseous exchange in the lung is improved as carbon dioxiderich gas is transported out of the lung allowing healthier lung regionsto expand.

Although the foregoing invention has been described in some detail, byway of illustration and example for-purposes of clarity ofunderstanding, it will be readily apparent to those of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims. It is also contemplated thatcombinations of the above described embodiments/variations orcombinations of the specific aspects of the above describedembodiments/variations are within the scope of this disclosure.

1. A method for altering the gaseous flow pathways within a lung suchthat gas may pass directly from lung parenchyma to an airway that islocated outside of a pleura surrounding the lung, said methodcomprising: advancing a device into a portion of said airway that isoutside of the pleura; creating an opening in said airway outside of thepleura with the device; fluidly coupling said lung parenchyma to theairway through the pleura such that gas may pass directly from the lungparenchyma to the airway and outside of the body wherein the step offluidly coupling comprises installing a conduit between said lungparenchyma and said airway, said conduit comprising a passageway for gasto flow through.
 2. The method of claim 1 wherein said opening iscreated using one device selected from the group consisting of amechanical member and a radio frequency energy delivering device.
 3. Themethod of claim 1, wherein said conduit comprises a first portion,second portion and a center section between said first portion and saidsecond portion, said first portion and said second portion being adaptedto secure said conduit to said lung pleura and said airway.
 4. Themethod of claim 3 wherein each of said first portion and second portionof said conduit comprises a plurality of extension members which aredeflectable such that when said conduit is deployed, said extensionmembers from said first portion substantially oppose said extensionmembers from said second portion such that tissue may be sandwichedtherebetween.
 5. The method of claim 3 wherein said center section has alength in the range of 0.5 to 50 mm.
 6. The method of claim 5 whereinthe center section has a length Of 1 mm.
 7. The method of claim 4wherein the extension members form right angles when deployed.
 8. Themethod of claim 4 wherein the extension members form angles between 90and 135 degrees when deployed.
 9. The method of claim 1, furthercomprising providing a sealant to an exterior surface of the conduit toprevent side flow of gas around the conduit.
 10. The method of claim 9wherein said sealant comprises talc.
 11. The method of claim 9 whereinsaid sealant is fibrin glue.
 12. The method of claim 9 wherein saidsealant comprises cyanoacrylate.
 13. The method of claim 1, wherein theconduit includes a biocompatible coating.
 14. The method of claim 13wherein said coating promotes wound healing.
 15. The method of claim 1,further comprising deploying at least one intrapleural conduit tomaintain a channel surgically created in an intrapleural airway.
 16. Themethod of claim 1, further comprising detecting blood vessels prior tosaid step of creating.
 17. The method of claim 1, wherein said conduitcomprises at least one visualization feature on an exterior surface ofsaid conduit.
 18. The method of claim 1, wherein said step of fluidlycoupling comprises creating a channel extending through said pleura andinto said lung parenchyma.
 19. The method of claim 1, further comprisingfixing a wall of said airway to a wall of said pleura.
 20. The method ofclaim 19 wherein said creating step is performed subsequent to saidfixing said airway wall to said pleura wall.
 21. The method of claim 20wherein said lung wall is the visceral pleura.
 22. The method of claim1, where the airway comprises an extra-pleural airway.
 23. The method ofclaim 22, where the extra-pleural airway comprises an airway selectedfrom the trachea or mainstem bronchus.
 24. The method of claim 1,wherein the gas may pass directly from the lung parenchyma, to theairway, through a natural respiratory opening, and outside of the body.